1/*
  2 * Copyright © 2008 Keith Packard <keithp@keithp.com>
  3 *
  4 * This file is free software; you can redistribute it and/or modify
  5 * it under the terms of version 2 of the GNU General Public License
  6 * as published by the Free Software Foundation.
  7 *
  8 * This program is distributed in the hope that it will be useful,
  9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 11 * GNU General Public License for more details.
 12 *
 13 * You should have received a copy of the GNU General Public License
 14 * along with this program; if not, write to the Free Software Foundation,
 15 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
 16 */
 17
 18#ifndef _LINUX_IO_MAPPING_H
 19#define _LINUX_IO_MAPPING_H
 20
 21#include <linux/types.h>
 22#include <linux/slab.h>
 23#include <linux/bug.h>
 24#include <asm/io.h>
 25#include <asm/page.h>
 26
 27/*
 28 * The io_mapping mechanism provides an abstraction for mapping
 29 * individual pages from an io device to the CPU in an efficient fashion.
 30 *
 31 * See Documentation/io-mapping.txt
 32 */
 33
 34#ifdef CONFIG_HAVE_ATOMIC_IOMAP
 35
 36#include <asm/iomap.h>
 37
 38struct io_mapping {
 39	resource_size_t base;
 40	unsigned long size;
 41	pgprot_t prot;
 
 42};
 43
 
 
 
 44/*
 45 * For small address space machines, mapping large objects
 46 * into the kernel virtual space isn't practical. Where
 47 * available, use fixmap support to dynamically map pages
 48 * of the object at run time.
 49 */
 50
 51static inline struct io_mapping *
 52io_mapping_create_wc(resource_size_t base, unsigned long size)
 
 
 53{
 54	struct io_mapping *iomap;
 55	pgprot_t prot;
 56
 57	iomap = kmalloc(sizeof(*iomap), GFP_KERNEL);
 58	if (!iomap)
 59		goto out_err;
 60
 61	if (iomap_create_wc(base, size, &prot))
 62		goto out_free;
 63
 64	iomap->base = base;
 65	iomap->size = size;
 66	iomap->prot = prot;
 67	return iomap;
 68
 69out_free:
 70	kfree(iomap);
 71out_err:
 72	return NULL;
 73}
 74
 75static inline void
 76io_mapping_free(struct io_mapping *mapping)
 77{
 78	iomap_free(mapping->base, mapping->size);
 79	kfree(mapping);
 80}
 81
 82/* Atomic map/unmap */
 83static inline void __iomem *
 84io_mapping_map_atomic_wc(struct io_mapping *mapping,
 85			 unsigned long offset)
 86{
 87	resource_size_t phys_addr;
 88	unsigned long pfn;
 89
 90	BUG_ON(offset >= mapping->size);
 91	phys_addr = mapping->base + offset;
 92	pfn = (unsigned long) (phys_addr >> PAGE_SHIFT);
 93	return iomap_atomic_prot_pfn(pfn, mapping->prot);
 94}
 95
 96static inline void
 97io_mapping_unmap_atomic(void __iomem *vaddr)
 98{
 99	iounmap_atomic(vaddr);
100}
101
102static inline void __iomem *
103io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset)
 
 
104{
105	resource_size_t phys_addr;
106
107	BUG_ON(offset >= mapping->size);
108	phys_addr = mapping->base + offset;
109
110	return ioremap_wc(phys_addr, PAGE_SIZE);
111}
112
113static inline void
114io_mapping_unmap(void __iomem *vaddr)
115{
116	iounmap(vaddr);
117}
118
119#else
120
121#include <linux/uaccess.h>
122
123/* this struct isn't actually defined anywhere */
124struct io_mapping;
125
126/* Create the io_mapping object*/
127static inline struct io_mapping *
128io_mapping_create_wc(resource_size_t base, unsigned long size)
 
 
129{
130	return (struct io_mapping __force *) ioremap_wc(base, size);
 
 
 
 
 
 
 
 
 
 
 
131}
132
133static inline void
134io_mapping_free(struct io_mapping *mapping)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
135{
136	iounmap((void __force __iomem *) mapping);
137}
138
139/* Atomic map/unmap */
140static inline void __iomem *
141io_mapping_map_atomic_wc(struct io_mapping *mapping,
142			 unsigned long offset)
143{
 
144	pagefault_disable();
145	return ((char __force __iomem *) mapping) + offset;
146}
147
148static inline void
149io_mapping_unmap_atomic(void __iomem *vaddr)
150{
 
151	pagefault_enable();
 
152}
153
154/* Non-atomic map/unmap */
155static inline void __iomem *
156io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset)
 
 
157{
158	return ((char __force __iomem *) mapping) + offset;
 
 
 
 
 
 
 
 
 
 
 
159}
160
161static inline void
162io_mapping_unmap(void __iomem *vaddr)
163{
 
 
164}
165
166#endif /* HAVE_ATOMIC_IOMAP */
167
168#endif /* _LINUX_IO_MAPPING_H */

  1/*
  2 * Copyright © 2008 Keith Packard <keithp@keithp.com>
  3 *
  4 * This file is free software; you can redistribute it and/or modify
  5 * it under the terms of version 2 of the GNU General Public License
  6 * as published by the Free Software Foundation.
  7 *
  8 * This program is distributed in the hope that it will be useful,
  9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 11 * GNU General Public License for more details.
 12 *
 13 * You should have received a copy of the GNU General Public License
 14 * along with this program; if not, write to the Free Software Foundation,
 15 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
 16 */
 17
 18#ifndef _LINUX_IO_MAPPING_H
 19#define _LINUX_IO_MAPPING_H
 20
 21#include <linux/types.h>
 22#include <linux/slab.h>
 23#include <linux/bug.h>
 24#include <linux/io.h>
 25#include <asm/page.h>
 26
 27/*
 28 * The io_mapping mechanism provides an abstraction for mapping
 29 * individual pages from an io device to the CPU in an efficient fashion.
 30 *
 31 * See Documentation/io-mapping.txt
 32 */
 33
 
 
 
 
 34struct io_mapping {
 35	resource_size_t base;
 36	unsigned long size;
 37	pgprot_t prot;
 38	void __iomem *iomem;
 39};
 40
 41#ifdef CONFIG_HAVE_ATOMIC_IOMAP
 42
 43#include <asm/iomap.h>
 44/*
 45 * For small address space machines, mapping large objects
 46 * into the kernel virtual space isn't practical. Where
 47 * available, use fixmap support to dynamically map pages
 48 * of the object at run time.
 49 */
 50
 51static inline struct io_mapping *
 52io_mapping_init_wc(struct io_mapping *iomap,
 53		   resource_size_t base,
 54		   unsigned long size)
 55{
 
 56	pgprot_t prot;
 57
 
 
 
 
 58	if (iomap_create_wc(base, size, &prot))
 59		return NULL;
 60
 61	iomap->base = base;
 62	iomap->size = size;
 63	iomap->prot = prot;
 64	return iomap;
 
 
 
 
 
 65}
 66
 67static inline void
 68io_mapping_fini(struct io_mapping *mapping)
 69{
 70	iomap_free(mapping->base, mapping->size);
 
 71}
 72
 73/* Atomic map/unmap */
 74static inline void __iomem *
 75io_mapping_map_atomic_wc(struct io_mapping *mapping,
 76			 unsigned long offset)
 77{
 78	resource_size_t phys_addr;
 79	unsigned long pfn;
 80
 81	BUG_ON(offset >= mapping->size);
 82	phys_addr = mapping->base + offset;
 83	pfn = (unsigned long) (phys_addr >> PAGE_SHIFT);
 84	return iomap_atomic_prot_pfn(pfn, mapping->prot);
 85}
 86
 87static inline void
 88io_mapping_unmap_atomic(void __iomem *vaddr)
 89{
 90	iounmap_atomic(vaddr);
 91}
 92
 93static inline void __iomem *
 94io_mapping_map_wc(struct io_mapping *mapping,
 95		  unsigned long offset,
 96		  unsigned long size)
 97{
 98	resource_size_t phys_addr;
 99
100	BUG_ON(offset >= mapping->size);
101	phys_addr = mapping->base + offset;
102
103	return ioremap_wc(phys_addr, size);
104}
105
106static inline void
107io_mapping_unmap(void __iomem *vaddr)
108{
109	iounmap(vaddr);
110}
111
112#else
113
114#include <linux/uaccess.h>
115#include <asm/pgtable.h>
 
 
116
117/* Create the io_mapping object*/
118static inline struct io_mapping *
119io_mapping_init_wc(struct io_mapping *iomap,
120		   resource_size_t base,
121		   unsigned long size)
122{
123	iomap->base = base;
124	iomap->size = size;
125	iomap->iomem = ioremap_wc(base, size);
126#if defined(pgprot_noncached_wc) /* archs can't agree on a name ... */
127	iomap->prot = pgprot_noncached_wc(PAGE_KERNEL);
128#elif defined(pgprot_writecombine)
129	iomap->prot = pgprot_writecombine(PAGE_KERNEL);
130#else
131	iomap->prot = pgprot_noncached(PAGE_KERNEL);
132#endif
133
134	return iomap;
135}
136
137static inline void
138io_mapping_fini(struct io_mapping *mapping)
139{
140	iounmap(mapping->iomem);
141}
142
143/* Non-atomic map/unmap */
144static inline void __iomem *
145io_mapping_map_wc(struct io_mapping *mapping,
146		  unsigned long offset,
147		  unsigned long size)
148{
149	return mapping->iomem + offset;
150}
151
152static inline void
153io_mapping_unmap(void __iomem *vaddr)
154{
 
155}
156
157/* Atomic map/unmap */
158static inline void __iomem *
159io_mapping_map_atomic_wc(struct io_mapping *mapping,
160			 unsigned long offset)
161{
162	preempt_disable();
163	pagefault_disable();
164	return io_mapping_map_wc(mapping, offset, PAGE_SIZE);
165}
166
167static inline void
168io_mapping_unmap_atomic(void __iomem *vaddr)
169{
170	io_mapping_unmap(vaddr);
171	pagefault_enable();
172	preempt_enable();
173}
174
175#endif /* HAVE_ATOMIC_IOMAP */
176
177static inline struct io_mapping *
178io_mapping_create_wc(resource_size_t base,
179		     unsigned long size)
180{
181	struct io_mapping *iomap;
182
183	iomap = kmalloc(sizeof(*iomap), GFP_KERNEL);
184	if (!iomap)
185		return NULL;
186
187	if (!io_mapping_init_wc(iomap, base, size)) {
188		kfree(iomap);
189		return NULL;
190	}
191
192	return iomap;
193}
194
195static inline void
196io_mapping_free(struct io_mapping *iomap)
197{
198	io_mapping_fini(iomap);
199	kfree(iomap);
200}
 
 
201
202#endif /* _LINUX_IO_MAPPING_H */